In addition to the other answers, you can call: single_term_title('Currently browsing: ') to display 'Currenty browsing term' (where term is the name of the taxonomy term you are viewing. (See Codex)

This works for custom taxonomies as well category and tag terms.

Also, you might find it easier to use wp_title which handles taxonomies and archives, displaying the appropriate title depending on what you are viewing. It essentially switches through all the available functions for displaying titles so you might want to take a look at the source code. Others include: